Interferometric methods for mapping static electric and magnetic fields

Giulio Pozzi, Marco Beleggia, Takeshi Kasama, Rafal E. Dunin-Borkowski

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    The mapping of static electric and magnetic fields using electron probes with a resolution and sensitivity that are sufficient to reveal nanoscale features in materials requires the use of phase-sensitive methods such as the shadow technique, coherent Foucault imaging and the Transport of Intensity Equation. Among these approaches, image-plane off-axis electron holography in the transmission electron microscope has acquired a prominent role thanks to its quantitative capabilities and broad range of applicability. After a brief overview of the main ideas and methods behind field mapping, we focus on theoretical models that form the basis of the quantitative interpretation of electron holographic data. We review the application of electron holography to a variety of samples (including electric fields associated with p–n junctions in semiconductors, quantized magnetic flux in superconductors and magnetization topographies in nanoparticles and other magnetic materials) and electron-optical geometries (including multiple biprism, amplitude and mixed-type set-ups). We conclude by highlighting the emerging perspectives of (i) three-dimensional field mapping using electron holographic tomography and (ii) the model-independent determination of the locations and magnitudes of field sources (electric charges and magnetic dipoles) directly from electron holographic data.
    Original languageFrench
    JournalComptes Rendus Physique
    Volume15
    Issue number2-3
    Pages (from-to)126-139
    ISSN1631-0705
    DOIs
    Publication statusPublished - 2014

    Keywords

    • Microscopie électronique en transmission
    • Holographie électronique
    • Cartographie de champs
    • Champs électriques
    • Champs magnétiques

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